I'm not sure how the younger crowd will feel about having a band like AC/DC perform at Coachella, considering their target audience is young adults, but I don't think it will cause havoc and mayhem amongst the new crowd. And it could welcome a new audience of fans that enjoy AC/DC and any other groups on the lineup. And hey, it worked well at Glastonbury last year when Metallica headlined, so needless to say I think the Coachella will be riding the Highway to Hell.
Classic rock and rave music aren't all that different, especially considering the eras each style comes from. Most ravers just want to hear music that moves them, and don't really care who is playing. It might help Coachella bring back some of its vibe from past years by trying something different like this.
I doubt the people who go to Coachella concerts will have a problem with classic rockers and ravers. I can imagine a large amount of people just go there to get high and hang out. I don't even know how much about music festivals these days are about the music for the people who frequent them.
Some doubt whether the mix of younger, newer, hipper artists with classic old school rockers such as AC/DC will work. But I have little doubt that it will. After all, with the innumerable band reunions that have been taking place over the last decade or so, many other music festivals have taken a similar approach and with great success.
A big draw of the Coachella festival has always been the eclectic nature of the line up. I think attendees appreciate good music, and any act that puts on a strong live show is always well received. AC/DC is very well known, and famous for an exciting live performance. I think that the classic rock will make a great addition to the festival.